Electromagnetic sound recording and reproducing machine



Oct. 15, 1-929. H. E. CHIPMAN ,ELECTROIAGNETIG SOUND RECORDING AND REPRODUCING IA CHINE Filed Jan. 51, 1927' 2 Sheets-Sheet 1 ATTORNEY Oct. 15, 1929. Y H. E. CHIPMAN 3 ELECTROIAGNETIC SOUND RECORDING AND REPRODUCING IACHINE Filed Jan. :51, 192v 2 Sheets-Sheet 2 35 Z9 7 v I INVENT R 33 Y g AATI'ORNEY Patented Oct. 15, 1929' UNITED STATES PATENT OFFICE HARRY E. CHIPMAN, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO ANDREW LE ROY CHIPMAN, OF NEW YORK, N. Y.

ELECTROMAGNETIC SOUND RECORDING AND REPRODUCING MACHINE Application filed January 31,

This invention relates to machines for recording and reproducing sounds electromagnetically and more particularly relates to. the mounting and movement of the re cording and reproducing unit and to the spool rotation.

Heretofore it has been customary to mount the recording and reproducing unit on a pivot thus causing the unit to swing in an are as the unit follows the record wire from one side of the spools to the other. Such arcuate movement places the wire under uneven and varying tension as the unit swings from side to side. This varying tension is objectionable since it is apt todistort the wire by stretching it and frequently is the cause of distorted recording and reproduction.

The'principal object of this invention is to mount said unit in such a way that it does not put the record wire under uneven and varying tension as the unit reciprocates and thus to overcome the objections referred to.

In accordance with this invention I mount the recording and reproducing unit to reciprocate in a straight line as the unit follows the record wire from one side of the spools to the other thus eliminating the placing of the record wire under uneven and varying tension and avoiding resulting distortion and excessive or injurious strain on the wire and unit.

In order that a clearer understanding of my invention may be had attention is hereby directed to the accompanying drawings forming part of this application and illustrating certain possible embodiments of my invention. Referring to the drawings Fig. 1 is a top view of a machine embodying this invention certain hidden parts being shown in dotted lines to show their location; Fig. 2 is asectional View of the top portion of the machine, and is taken on the line 2-2 of Fig. 1; and Figs. 3 and'4 are sectional views of details of the machine, and are taken respectively on the lines. 33 and 4-4 of Fig. 2.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

Referring to the drawings, there is a suit- 1927. Serial No. 164,669.

able base or support, usually in theform of a box or' cabinet, having a top plate 1 supporting brackets 2 on which are journaled the shafts 3 and 4 which carry the record wire spools 5 and 6. These shafts are driven by conventional mechanism, including pulley wheels 7, 8 and 9 and belts 10 and 11. Another shaft, 12, journaled in brackets 13, carries a worm wheel 14 driven by worm gear 15 onshaft 3. Gear 16 on shaft 12 meshes with a gear 17 on a shaft 18 which carries the cam 19 which controls the movement of the recording and reproducing unit 20.

Recording head 20 may be of conventional design and construction. It is supported on a pin 21 which is adapted to be adjustably secured in a socket 22 by means of a set screw 23; Socket 22 is formed on or secured to a plate 24 which is supported by fixed guide plates 25 so as to be slidable in a straight line', plates 25 having edge flanges 26 seating in grooves 27 in the sides of plate 24. Cam 19 engages a cam roller 50 carried on a cam block 28' which is slidably confined bet-ween two guide members 29 and 30, secured to top plate 1,'and a rod 31,.slidably steadied by a strap member 32, connects the block 29 to the plate 24. A spring 33 engaged between a pin 34 on plate 24 and a fixed pin 35 maintains block 28 against cam roller so that as cam 19 revolves the plate 24 and the unit 20 supported thereon will move back and forth in a. straight line between and parallel to the axes of the spools 5 and 6 at a uniform speed adapted to cause the recordribbon 36 to wind on the spools in even, fiat layers. Thus the movement of the unit 20 from one side of the spools to the other does not place uneven and varying tension on the record wire, and distortion of the record and objectionable strain on the parts are avoided.

It will be noted that the shafts 3 and 4 are mounted in a horizontal plane, and that the unit 20 reciprocates in a horizontal plane.

To prevent the spools from overrunning, and the consequent unwinding of the record ribbon from one spool faster than it is being wound up on the other, which would result in the record ribbon becoming tangled, I provide a friction drag device for each shaft 3 and 4.- Each drag includes a disc 40, secured to the shaft, and a cooperating adjacent disc 41 through which the shaft extends rotatably, disc 41 being held stationary by means of a finger 42 extending from the disc. and'disposed between two stop plates 43 secured to the top 1 of the machine. A spring 44 is compressed between disc 41 and a knurled nut 45, mounted for adjustment on a threaded portion 46 of the shaft, and this spring presses the disc 41 against the disc 40 in accordance with the adjusted tension of the spring, thus establishing a friction drag effect between the discs 40 and 41 in opposition to free rotation in either direction of the shaft and the spool carried thereon. Preferably the contact face of one of the discs, such as disc 40, has insert-s 47 of cork or other suitable material. To adjust the force of the drag it is merely necessary to adjust the nut 45 nearer to or further from the discs.

As many changes could be made in the above construction and as many apparently widely different embodiments of this invention could be made without departing from the cope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrativeand not in a limiting sense.

What I claim is 1. In an apparatus of the character described, in combination, a recordingand reproducing unit, means supporting said unit for reciprocation in a strai ht line, said supporting means including fixed guide members, a plate slidably mounted on said guide members, a socket on said plate, and a.pin adjustably fixed in said socket, the recording and reproducing unit being carried; on said pin, and means for reciprocating said plate and unit.

2. In an apparatus of the character described, in combination, fixed guide members, a plate slidably mounted on said guide members, a socket on said plate, a pin adjustably fixed in said socket, a recording and reproducing unit carried on said pin, a cam block, guide members for the block, a rod connecting the cam block with said plate, and means, including a cam engaging said cam block, for reciprocating said plate and unit in a straight line.

3. In an apparatus of the character described, a rotatable shaft, means for rotating the shaft, a disc fixed on said shaft for revolution therewith, a non-rotatable disc movable axially againstthe rotatable disc, and means for pressing the movable disc against the rotating disc to establish drag resistance to the revolution of said shaft.

4. In an apparatus of the character described, a rotatable shaft, means for rotating the shaft, a disc fixed on said shaft for revolution therewith, a non-rotatable disc movable axially against the rotatable disc, and means for pressing the movable disc against the rotating disc to establish drag resistance to the revolution of said shaft, said means including an adjustable member on said shaft and a spring compressed between said memher and the movable disc.

5.- Inan apparatus of the character 'decompressed between said member and the movable disc.

6. In an electro-magnetic sound recording and reproducing machine, a rotatable shaft, a reel mounted on said shaft, means for rotating said shaft, a disk fixed on said shaft for revolution therewith, and a non-' rotatable disk adapted to be moved axially against the rotatable disk to establish drag resistance to the revolution of said shaft.

7. In an electro-magnetic sound recording and reproducing machine, in combination, a

pair of reels, means for rotating said reels to cause recording wire to be transferred from one reel to the other, a disk fixed to each of said reels for rotation'therewith, a non-rotatable disk associated with each of said rotatable disks and adapted to be moved axially thereagainst to establish drag resistance and to prevent said reels from over-running, a recording and reproducing machine disposed between said reels and adapted to engage the recording wire as it passes from one reel to the other, and means for reciprocating sai 1i unit in a straight line with respect to said ree s.

This specification signed this 27th day of January, 1927.

HARRY E. CHIPMAN. 

